The 8310 and 8320 Electromagnetic Locks come with screws installed in the housing. These screws, when in place, inhibit the insertion of an Allen wrench into the mounting screw openings on the underside of the lock. These screws will need to be removed prior to installing the lock so as to allow the mounting plate to be removed from the top of the lock. Fig 3 illustrates the location of these screws. One screw acts solely to inhibit tampering while the screw on the other end discourages tampering while holding the cavity cover in place